Dubbed the first “mumble-noir” when it bowed at last year’s South by South west Film Festival, Aaron Katz’s “Cold Weather” weds half-hearted thriller elements to the self-absorbed, no-budget mumblecore films pioneered by Katz in efforts like “Dance Party, USA.”

The uncharismatic Cris Lankenau, a veteran of Katz’s “Quiet City,” plays a 20-something college dropout who works at an ice factory and lives with his sister (Trieste Kelly Dunn) in Portland, Ore.

Not much happens during the first half-hour or so — there’s a surfeit of beautifully photographed scenic shots throughout. Eventually our hero, a Sherlock Holmes fan, decides to investigate the disappearance of an ex-girlfriend (Robyn Rikoon) who returns to Portland.

“Cold Weather” is much less interested in providing a satisfying mystery than dwelling on the quirks of its aimless and awkward protagonist — anyone unwilling to go along risks severe boredom.